Density Calculator

Calculate density, mass, or volume from the other two values.

By Konstantin Iakovlev · Updated September 2026 · Source: USGS Water Science School: Water Density

Density

2.0000 g/mL

Mass

100.00 g

D = M / V

Density2.0000 g/mL
Mass100.00 g
Volume50.00 mL

Use the Density Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.

Disclaimer: This calculator is for informational purposes only. Results are estimates based on the information you provide and the assumptions described on this page.

How It Works

Give this tool any two of the three quantities, density, mass, or volume, and it returns the third. That small piece of arithmetic comes up across chemistry, physics, and engineering. For engineers, scientists, and students working through harder problems, the relationship between these three properties is bedrock.

Everything rests on one equation, Density (ρ) = Mass (m) / Volume (V), which rearranges cleanly to solve for the others: m = ρ * V when you need mass, or V = m / ρ when you need volume. You choose which quantity to solve for and enter the other two in the calculator's fixed units: grams, milliliters, and grams per milliliter (1 g/mL is the same as 1 g/cm³ or 1,000 kg/m³). There is no unit converter, so convert kilograms, liters, or pounds before you enter them.

Units trip people up more than the math does, so confirm you haven't mixed grams with kilograms or milliliters with liters before converting. Watch your significant figures too, since the precision of what you type sets the precision of what you get back. Temperature is the subtler factor: most materials expand as they warm, so their density falls, which is worth accounting for whenever accuracy is critical.

Example: Checking the Density of a Sample

  1. 1 A lab sample has a mass of 15 g. Lowered into a graduated cylinder of water, it raises the level by 7.5 mL, so its volume is 7.5 mL.
  2. 2 Choose 'Density (given mass, volume)' and enter 15 for mass and 7.5 for volume. Density = 15 g / 7.5 mL.
  3. 3 The calculator shows a density of 2.0000 g/mL, which is 2,000 kg/m³.
  4. 4 That is about twice the density of water (USGS lists 0.99802 g/cm³ at 21 °C), so the sample sinks. To check it against a material specification, compare with the density the supplier gives for the same temperature.

Source: USGS Water Science School: Water Density · Last updated: September 2026

Frequently Asked Questions

How do I calculate density?
Density equals mass divided by volume. In metric units, water has a density of 1.0 g/cm3, which is a useful reference point. Objects with a density greater than water sink in water, while those with lower density float.
What are common density units?
Common units include g/cm3 (grams per cubic centimeter), kg/m3 (kilograms per cubic meter), and lb/ft3 (pounds per cubic foot). To convert g/cm3 to kg/m3, multiply by 1,000. Water is 1.0 g/cm3, 1,000 kg/m3, or 62.4 lb/ft3.
How does temperature affect density?
Most materials become less dense as temperature increases because they expand. Water is an exception between 0 and 4 degrees Celsius, where it becomes denser as it warms, so the coldest water stays at the surface of a lake, which is where it freezes first. Ice floats for a separate reason: its crystal lattice holds the molecules farther apart, so ice is about 9% less dense than liquid water.

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